Can backlight/inverter cause random freeze/restart?

By antonea
Mar 25, 2008
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  1. Hey!

    I was having this issue with my laptop freezing or restarting. I started up my computer to try to fix that problem a few days ago and noticed that I could faintly see anything on my screen. I don't know what that issue is, but can that in anyway be linked to my random restart/freeze problem? Or am I just lucky enough to have two problems at once! haha
  2. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

    I'd say normally no.
    I've seen a lot of inverter boards go, but no other fault associated

    But it is possible I suppose
  3. lamo

    lamo Newcomer, in training Posts: 570

    antonea, tell exact model of laptop
  4. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,675   +152

    Your backlight or inverter is bad. Try connecting an external monitor and see if the image is normal. The restarting and freezing may be caused by a bad or loose hard drive. This can be caused by memory too. I don't think the freezing and video problems are related
  5. antonea

    antonea Newcomer, in training Topic Starter Posts: 37

    well, on startup the BIO's splash page flickers to its normal bright color for a quick second. would that help indicate if its the inverter or backlight?
  6. Tmagic650

    Tmagic650 TS Ambassador Posts: 20,675   +152

    So you didn't connect an external monitor? Still do so if you can. The bright flash may mean Inverter, but it can also indicate a bad video chip (motherboard) The functioning external monitor will tell us if the motherboard is good
  7. antonea

    antonea Newcomer, in training Topic Starter Posts: 37

    im sorry! i forgot you told me to plug an external monitor in...well i did and it seems my computer problems are never just black and white:
    i plugged my monitor in and my laptop showed up clear as daylight, but after the windows xp loading screen my monitor went into power save mode and acted like there was still a computer running but well...was asleep. so i checked my laptop screen and i was able to faintly see my welcome screen and then desktop.

    ideas?
  8. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

    When the monitor goes into that power save mode, hold down the Fn key and press F8
  9. antonea

    antonea Newcomer, in training Topic Starter Posts: 37

    ok, well anyways...since the monitor works what does this mean for my laptop screen??
  10. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

    That took a whole day to answer (don't take offence but Tmagic650 wanted an answer a while back now!)

    Anyway, start with removing the display bezel, and checking the Inverter board (ie unplug replug, and seeing it looks burnt out)
    Hardware experience required, also referring to manual for Power and antistatic precautions. The Inverter board is high voltage !
  11. antonea

    antonea Newcomer, in training Topic Starter Posts: 37

    ha, yea sorry i didnt mean to take so long! my mind comes and goes...ok. i will take a look at it ...right now and report back and let you know how things go/look!
     
  12. antonea

    antonea Newcomer, in training Topic Starter Posts: 37

    ok, well i checked the inverter connection and unpluuged and replugged it. is there any other sort of connection i should check while it is still open?
  13. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

    Yes you can remove the LCD and check the back data cable too

    Was I too late?
  14. antonea

    antonea Newcomer, in training Topic Starter Posts: 37

    no, but i dont even know what the back data cable is!!!
  15. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

    Usually an orange flat ribbon cable, plugged into the back of the LCD

    Also does the inverter look ok?
  16. antonea

    antonea Newcomer, in training Topic Starter Posts: 37

    yea, i believe so. i dont see anything going on there that would lead me to believe anything is wrong with it. anything specific i should look for on the inverter that would clue its bad?
  17. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

    Actually just looking won't confirm faulty (obviously :) )
    But sometimes you may see it black all the plasic cover even looking grey and dirty (showing signs of burn out)

    Anyway get the part number stamped on it (4 sequential numbers I think)
    And search
  18. antonea

    antonea Newcomer, in training Topic Starter Posts: 37

    well, ive disconnected and reconnected everything...connectible back there. and nothing looks burnt...so whats the news? haha
     
  19. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

    Find that inverter board, somewhere for sale, order it install it, and test

    Then reply back here, in a weeks time!

    Note: This might work (but that's what I'd do)

    To save the reply, I don't know where, just keep searching, ask around. (someone's got one no doubt.)
  20. Kegtapper

    Kegtapper Newcomer, in training Posts: 23

    here's a tip
    look on the inverter board near the video connector (usually to the left) there may be markings. F1 that is a fuse. small as it may be, you can check it with a meter and see if you have > 1 Ohm if YES fuse is good.

    If no reading the fuse is blown (open). replace inverter

    I carry a backlight tube in my Go-Kit to test backlights. Since there isn't much of a way to test them unless your ohmmeter has Khz reading. Then you can hold the meter probes near the pink/white wires. Now I will have to get a neon glow tester, that may also read whether voltage is being output to the backlight.
  21. roland_xp_80

    roland_xp_80 Newcomer, in training

    check all the lastest driver..
  22. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

    This is not a Windows driver issue, as Windows has not even started
    It is a hardware issue
  23. Kegtapper

    Kegtapper Newcomer, in training Posts: 23

    Backlight issue

    From his last description, I'd bet a donut to a dollar that it is his inverter.

    Cannot generate enough current to ignite the tube, similar to flickering Flourescent lamps at the 24 hour laundamat. (But those are called starters)
  24. kimsland

    kimsland Ex-TechSpotter Posts: 18,353

    My fish tank fluro started flickering yesterday, so I bought a starter (tried two), and it's still flickring !! I'll buy a tube now I suppose.

    Just wrote that because of the keywords starter and fluro (Totally unrelated lol)

    Edit:

    Tube fixed it
  25. Kegtapper

    Kegtapper Newcomer, in training Posts: 23

    Hey, I don't diagnose fish tank lamps!!! BTW- in your case I wouldn't have guessed the starter. Why? primarily because it stays on all the time. ON/OFF daily on a flourescent lamp can kill a starter.

    But the biggest and heavest piece on those grocery store lights- "the ballast" type transformer would be equiv. to the small transformers on the OP inverter.

    Since the Chinese have Babelized the electronics industry, its next to impossible to find another, except in same model. Even then it may be different.
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